The first thing to do would be to speak to the port police that have an office above Gregg's patisserie, they will advise on what paperwork you need, I believe you will need to go to the tax office and pay a tax (surprise surprise) then you will need to go back to the port police and get a 'green card' this will tell you what you will need to keep on board, ie:- day/night flashes, life jackets, fire extinguishers etc etc, if you know Gregg then he could take you up to the office and help, he did this for my father-in-law. I know spaces in that harbour are a premium but you may be able to talk to the fishermen and see if there are any spaces that they are not using but paying for, you could then pay them.
I hope this may be of some help,
regards
glenick